This application is related to Japanese application No. 2002-087921 filed on Mar. 27, 2002, whose priority is claimed under 35 USC xc2xa7119, the disclosure of which is incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a plasma display panel in which light emitting regions are selected by address electrodes and display is performed by making use of gas discharge between a pair of sustain electrodes. In particular, it relates to a plasma display panel having the sustain electrodes and the address electrodes of improved structure.
2. Description of Related Art
A plasma display panel (PDP) to which light emission by electric discharge is applied has conventionally been used as a large and thin display device. The conventional PDP includes, as shown in FIG. 9, a front substrate 100, a rear substrate 200 and mixture gas of neon/xenon or helium/xenon which is filled as discharge gas between the front substrate 100 and the rear substrate 200. On an inner surface of a glass substrate 111 which serves as a base material of the front substrate 100, a plurality of sustain electrode pairs 110 each including a first sustain electrode 114 and a second sustain electrode 113 for causing surface discharge for display are arranged parallel to each other. The first and second sustain electrodes 114 and 113 are covered with a dielectric layer 115 for AC driving and the surface of the dielectric layer 115 is covered with a protective layer 116. The first and second sustain electrodes 114 and 113 each include transparent conductive films 114b and 113b and bus electrodes 113a and 114a of a metal film for ensuring the conductivity.
On an inner surface of a glass substrate 221 which serves as a base material of the rear substrate 200, a plurality of address electrodes 222 for selecting a unit light emitting region in cooperation with the second sustain electrodes 113 are arranged to cross the sustain electrode pairs 110 arranged on the front substrate 100. The address electrodes 222 are covered with a dielectric layer 223 and straight belt-shaped (stripe-shaped) ribs 224 for dividing discharge space are provided on the dielectric layer 223 such that each of which is positioned between two adjacent address electrodes 222. The ribs 224 divide the discharge space into unit light emitting regions along a line direction (pixel arranging direction parallel to the sustain electrodes). In a plurality of concave portions formed of the ribs 224 and the dielectric layer 223, which serve as the discharge spaces, fluorescent layers of R, G and B are arranged in a stripe pattern. The fluorescent layers 225 are excited by ultraviolet rays generated by surface discharge, thereby causing light emission. In this PDP, three adjacent unit light emitting regions (subpixels) comprise a single display pixel. Each of the unit light emitting regions comprises a display cell defined by the first and second sustain electrodes 114 and 113 and an address cell defined between the second sustain electrode 113 and the address electrode 222.
With the above-described structure, display is performed as follows. First, a unit light emitting region is selected by causing address discharge in the address cell between the second sustain electrode 113 of the front substrate 100 and the address electrode 222 of the rear substrate 200. Then, a sustain voltage is applied to the sustain electrode pair 110 to cause discharge only in the display cell of the selected unit light emitting region. Thereby, the fluorescent layers 225 are excited by the ultraviolet rays to emit light.
As another prior art PDP, there is a PDP of ALIS(Alternate lighting of Surfaces) type in which surface discharge for display is caused between adjacent sustain electrodes arranged at regular intervals to realize high resolution and increased pixel number.
The stripe-shaped ribs 225, which are adopted as the mainstream of the panel structure, do not include ribs formed along the arranging direction of the sustain electrodes 113 and 114. Accordingly, discharge interference is apt to occur along the arranging direction of the sustain electrodes 113 and 114, i.e., along the stripe-shaped ribs 225. Therefore, with a view of separating the discharge, width of a reverse slit RS (non-discharge gap) between adjacent sustain electrode pairs 100 where the discharge is not caused is expanded as compared with a slit S (discharge gap) between the paired sustain electrodes 114 and 113 where the discharge is caused. However, as the high resolution progresses and the pixel number increases, the width of the reverse slit RS is reduced and a sufficient distance for separating the discharge cannot be maintained. As shown in FIG. 10, when a sustain voltage is applied to the first sustain electrodes 114 to cause discharge A1 and A3 in the display cells of D1 and D3, the discharge A1 or A3 extends to the display cell D2 adjacent along the stripe-shaped rib 225. That is, discharge interference occurs to cause false discharge A2 (excessive discharge) in the display cell D2, which makes the light emitting operations unstable.
In the other prior art PDP, discharge occurs on both sides of each sustain electrode. Therefore, the interference is prevented by drive control. However, in the case where a pixel pitch along the column direction is reduced for higher resolution, the discharge interference as described above occurs in the column direction, which makes the operations unstable.
To solve the above-described problems, the present invention intends to provide a PDP which inhibits the discharge interference along the arranging direction of the sustain electrodes without increasing the distance between two adjacent sustain electrode pairs.
The present invention provides a plasma display panel comprising a first substrate and a second substrate opposed to each other, a plurality of sustain electrodes arranged parallel to each other on an inside surface of the first substrate, a plurality of ribs arranged orthogonally to the sustain electrodes on an inside surface of the second substrate, and elongated address electrodes each arranged between adjacent ribs, wherein adjacent sustain electrodes have a pair of protrusions oppositely projected in a direction approaching each other and one of the pairs of protrusions of two adjacent sustain electrode pairs is displaced from the other pair of protrusions along the sustain electrodes between the ribs.
These and other objects of the present application will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.